Tiltable searchlight having a high power arc lamp



Sept 29, 1936. c. BUCHELE ET AL' TILTABLE SEARCHLIGHT HAVING A HIGH POWER ARC LAMP Filed Oct. 15, 1935 fnvenzors: QM W Patented Sept. 29, 1936 UNITED STATES PATENT OFFICE TILTABLE SEARCHLIGHT HAVING A HIGH POWER ARC LAllfl Carl Biichele and Karl Prinz, Jena, Germany, assignors to the firm of Carl Zeiss, Jena, Germany Application October 15, 1935, Serial No. 45,079 In Germany October 20, 1934 4 Claims. (Cl. 176-119) We have filed an application in Germany, and is rotatable about an axis parallel to a hori- October 20, 1934. zontal axis of rotation of the search light, and In high-power arc-lamps having electrodes inwhich is coupled to the cathode sleeve, for inclined relatively to each other, the smooth burnstance by means of the curved guide mentioned 5 ing and the efiiciency of the light depend largely above. Pendulums for an automatic control of 5 on the positions the axes of the electrodes assume the cathode can be used eventually also for comrelatively to each other. It is therefore essential pensating the search-light rotation about a pluthat the electrodes are so arranged relatively to rality of axes. each other that the arc is given the correct shape. In the following, which is a further description which is dependent upon the currents of air of the invention, reference is had to the accom- 10 arising when the lamp is burning. Accordingly, 'panying drawing. when the lamp burns in a position other than the In this drawing, Figures 1 and 2 illustrate the normal one, in which the search-light axis is desired reciprocal positions of the electrodes in generally horizontal, the changed currents of air two different search-light positions; Figure 3 make the light-arc assume another shape, and represents a constructional example of an arc- 15 this especially when the changes of position are lamp without search-light housing; and Figure 4 comparatively great, for instance after an upis a lateral view of a search-light which is rotatward rotation of the search-light through an anable about a horizontal axis and of a different gle of 90 or more. A departure from the original constructional form. In all these figures, the

shape of the light-arc may give rise to very noanode and the cathode are designated A and B, 20

ticeable disturbances especially in automatically respectively. controlling lamps, since the variation of resist- Figure 1 shows the electrodes in the normal ance due to a different shape of the arc very often search-light position. The cathode axis UU is entails such a length of this arc as is substaninclined at an angle a relative to the anode axis tially different from the normal one, provided, of VV and intersects the end face of the anode A 25 course, that the electric voltage of the lamp reat the point A To ensure a correct burning, mains unchanged. this point A does not coincide with, but is dis- According to the invention, the effects of alterplaced by a: relatively to, the centre of the end ations of the light-arc in high-power arc-lamps is face. When the search-light is rotated for inneutralized by making the position of the cathode stance upwardly through an angle of 180", the 30 axis relative to the position of the anode axis so electrodes assume the positions represented in respond automatically to any inclination of the Figure 2. According to the invention, this rolamp relative to a vertical line that the cathode tatlon automatically so changes the axial posiaxis is always given relatively to the anode the tion of the cathode B according to the searchposition most favourable for the angle between light adjustment that the axis UU intersects 35 the said vertical line and the axis of the searchthe said end face at the point A This point A light. Experiments have proved that it is possiis displaced by x relatively to the centre of the ble in this manner to rotate the search-light end face, A being at that side of the said centre even more than through an angle of 180 without which is opposite A Accordingly, the changed 40 an interruption of the light-arc having to be air-currents and other conditions are taken into 40 feared. account.

' It is advisable to provide that the cathode sleeve In the lamp according to Figure 3, the cathode be rotated about an axis and to use for the B is held by a sleeve a rotatable about a pinion adjustment of the cathode holder relative to this cm a support I) resting on a base N. The

axis a curved guide, for instance an eccentric sleeve a is connected to the support b also by body whose axis of rotation is parallel to that of a rod (1 which is longitudinally displaceable in a the cathode sleeve. ring e fixed to the support b. Between this ring The automatic adjustment of the cathode can e and a collar d fast with the rod (1 is provided be efiected by means of a wheel gear transmita helical spring I which presses the sleeve a ting the movement of the search-light housing against an eccentric body g. This body g is so 50 to the cathode. Another suitable kind of automounted on the support b as to be rotatable about matic compensation of the rotation about a an axle 9 to which a pendulum g is attached. definite axis is obtained when the adjustment of When the lamp 'is rotated upwardly, the penthe cathode sleeve is effected by a pendulum dulum g and, accordingly, the eccentric body g which is mounted in the search-light housing remain in their positions relative to space. As 58 a consequence thereof, the position of the eccentric body 9 relative to the sleeve a is changed, which means that also the positions of the sleeve a and the angle a are altered. Subsequently to the lamp having been rotated through 180, the angle on has become a and the point at which the axis UU intersects the end face of the anode A has travelled from A to A In the constructional example according to Figure 4, a toothed wheel a is substituted for the pendulum g The base b is rotatable about an axle i in a support, for instance in a fork b resting on a foot b The toothed wheel a is in mesh with a toothed wheel a of equal diameter, this wheel a being fixed to the aXis of rotation i of the search-light housing. Accordingly, the desired cathode displacement is possible also by means of this construction.

We claim:

1. In a search-light, a high-power arc-lamp containing a cathode and an anode inclined relatively to each other at an obtuse angle, a rotary base for the lamp, and a support for the base, this base being adjustable in the support relatively to a vertical line, means for automatically adlusting the angle of inclination of the cathode relatively to the anode according to the inclination of the said base relative to the vertical line.

2. In a search-light, a high-power arc-lamp containing a cathode and an anode inclined relatively to each other at an obtuse angle, a base for the lamp, and a support for the base, a cathode sleeve, and a cathode support rigidly connected to the said base, the cathode sleeve being mounted on this cathode support and rotatable about an axis at right angles to the plane containing the axis of the cathode and anode, an eccentric body for adjusting the cathode sleeve on its axis of rotation, and means coupled to the eccentric body and adapted to automatically adjust in combination with this body the angle of inclination of the cathode relatively to the anode according to the adjustment of the said base relative to the vertical line.

3. In a search-light, a high-power arc-lamp containing a cathode and an anode inclined relatively to each other at an obtuse angle, a base for the lamp, and a support, the base being so disposed in this support as to be rotatable about a horizontal axis, a cathode sleeve and a cathode support rigidly connected to the said base, the cathode sleeve being mounted on this cathode support and rotatable about an axis at right angles to the plane containing the axis of the cathode and anode, an eccentric body for adjusting the cathode sleeve on its axis of rotation, a gear comprising two wheels, the one of these Wheels cooperating with the eccentric. body, and the other of these wheels being rigidly so connected to the said support for the base as to be concentric to the said axis of rotation of the base.

4. In a search-light, a high-power arc-lamp containing a cathode and ananode inclined relatively to each other at an obtuse angle, a base for the lamp, and a support, the base being so disposed in this support as to be rotatable about a horizontal axis, a cathode sleeve and a cathode support rigidly connected to the said base, the cathode sleeve being mounted on this cathode support and rotatable about an axis at right angles to the plane containing the axis of the cathode and anode, an eccentric body for adjusting the cathode sleeve on its axis of rotation, and a pendulum so suspended on the said cathode support as to be rotatable about an axle parallel to the said horizontal axis of rotation of the said base.

CARL B'U'CHELE. KARL PRINZ. 

